Crane & Hoist Drive

Unico offers both AC and DC solutions for the crane industry. Either type of drive can be configured for gantry, steel mill, portal, or offshore applications. Axis-specific software for hoist, bridge, or trolley motions is built into the drive.
UNICO’s Crane and Hoist Drive combines the proven performance and versatility of

UNICO’s 2000 Series drives with powerful control software engineered specifically for hoist, bridge, and trolley applications. The drive is completely engineered and manufactured in the U. S. A. Thousands of rugged 2000 Series controllers are in use in AC and DC servo-positioning systems worldwide.

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Common Bus Design

 A common bus design reduces system complexity while minimizing power consumption. Unlike other drive systems, where each drive has its own integral rectifier, the 2000 Series employs a single charging unit for all drives in the system. This reduces panel space and spare part requirements while cutting installation costs. One common dynamic braking resistor grid is used for all motions.

Crane hoist diagram

Energy Sharing

With the common bus design, regenerated energy can be circulated within the system to be reused by motoring drives rather than dissipated wastefully by the dynamic braking resistors. Such energy sharing can substantially reduce electrical operating costs on some multimotor operations.

Redundant Charging Unit

For optimal safety and reliability, a redundant charing unit can be added to protect against crane immobility. This backup unit permits continued operation without loss of control should the primary charging unit fail.

Universal Drive

The unique 2000 Series can control a DC motor today and an AC motor tomorrow. By replacing troublesome electromechanical controls with reliable, solid-state technology, the drive can immediately improve crane operation, safety, and productivity while retaining the existing DC rails and motor. With a small modification, the same drive can be converted to flux vector AC operation, allowing the DC motor to be replaced with a low-maintenance AC induction motor the next time repair is needed. With its low profile and small footprint, the drive can usually be installed within existing enclosures for efficient retrofitting with minimal downtime.

Optimized Transducerless Operation

Proprietary velocity observer software yields excellent speed regulation for singleand multimotor operation without motor-mounted encoders. If transducer feedback is required, the drive supports 5 V and 15 V encoders, resolvers, and linear absolute encoders.

Motor and Brake Torque Proving

Precise coordination between motor and brake dramatically extends brake life and lowers maintenance costs. Because the drive completely controls motor torque, a brake is required only for holding and emergency stopping in case of power outages or faults. An adjustable load hang time further minimizes brake wear.

PLC Communications

The drive can be connected serially to most major brands of programmable controllers for easy integration into a system.

Integral Crane Automation

With optional IEC 1131 open-architecture logic programming, a drive with coprocessor can control up to 16 or 32 independent I/O points. This eliminates external relays, timers, and related wiring. Programming can be done by the user or by UNICO engineers in ladder logic or any of four other IEC 1131 languages.

AC or DC Inputs and Outputs

On-board, optically isolated converters configure individual inputs and outputs to the control voltage requirements of a particular system. A mixture of AC and DC inputs ranging from 24 V to 250 V can be applied on each motion. No add-on I/O boards are required.

Plain-Language Setup and Diagnostics

An easy-to-read two-line by 24-character-per-line descriptive display shows setups, readouts, and fault messages in plain English, not cryptic codes. Faults are logged by time and date with the 50 most recent occurrences being retained for review. Windows-based monitoring software and an interactive CD-ROM troubleshooting guide are also available.


  • Warp-speed quick lift
  • Reverse plug simulation
  • Load hang time
  • Motor and brake torque proving
  • Fast stop
  • Variable-speed control
  • Five preset speeds
  • Analog joystick control
  • Microspeed positioning control
  • Dual upper/lower limit switch inputs
  • Torque limit
  • Torque limited accel/decel times
  • Stepless acceleration/deceleration
  • Mechanical resonance filters
  • Hoist overload protection
  • Slack cable detection
  • Uncommanded motion detection
  • Antisway control
  • Automatic self-tuning to motor and load
  • Keypad security lockout


  • High-speed digital signal processor and patented digital current regulator provide superior speed and torque control
  • Operates AC or DC motor from AC or DC source
  • Single power drop reduces power distribution requirements
  • Twelve-pulse and fully regenerative options for optimal power quality
  • True load sharing capability
  • Analog voltage or current speed references
  • Superior motor protection

DC Retrofits

  • Replaces high-maintenance electromechanical controls with reliable, low-maintenance, solid-state technology
  • Retains existing DC motors
  • Powered by existing 250 V DC rails
  • Antiregeneration diode isolates drive from the rails
  • Provides speed and torque control superior to electromechanical contactors
  • Eliminates commutator faults due to brownouts
  • Provides load-independent hoist and lower speeds
  • Engages brake after motion has stopped (load hanging)
  • Minimizes brake wear by eliminating the need to engage brake when going from up to down motion
  • Reduces line voltage notching
  • Reduces motor heating
  • DC IGBT-based PWM technology ensures peak motor efficiency
  • Compact design permits reuse of existing enclosures
  • Utilizes existing crane controls until update is desired


  “Clunk-O-Tronics” UNICO 2000 Series
Maintenance High Reduced
Life Typically low Reduced heating extends life
Commutation faults Yes Minimal
Protection Bimetallic or eutectic Software controlled
Change to AC in future No Yes
Load hanging Brake captures the spinning load Brake engaged only after motor stops
Engaged when changing directions Yes—necessitates brake maintenance No—extends brake life
Maintenance High Reduced by at least 90%
Maintenance Yes None
Crane Operation
Current control Performance depends upon motor temperature, age, brushes, etc. Current to motor controlled using digital current regulator (U. S. patent)
Lowering speed Varies with load Independent of load
Notch filters No Yes—eliminates resonance
Line voltage notching Yes No
Load stabilization control No Yes
Speed adjustments New resistors Setup parameters
S-ramp setup S-ramp setup Yes
Diagnostics No Last 50 faults with date/time stamping
Programmable security No Yes
Windows/PC setup No Yes (software available)
On-board PLC functions No Optional


Input Supply
Voltage 208/230, 380/400/415/460, or 575 V AC (±10%), 3-phase 250 V DC (+20%/–25%)
Frequency 47 to 63 Hz
Displacement Power Factor 0.95 at all loads and speeds
1.0 with regeneration
Output Rating
Voltage Zero to input voltage
AC Switching Frequency 10 kHz standard, programmable 5 to 20 kHz
DC Switching Frequency 1.5 kHz
Overload Current 150% of rated for 1 minute, 200% for 3 seconds
Operating Temperature Less than 300 hp: 32° to 131° F (0° to 55° C)
300 hp or more: 32° to 104° F (0° to 40° C)
Storage Temperature 5° to 158° F (–15° to 70° C)
Ground fault Heat sink overtemperature
Oversized IGBT power section Power transistor fault
AC line input fuses DC link choke
DC bus overvoltage • Phase loss
DC bus undervoltage Control power undervoltage
DC bus pre-charge contactor Excessive velocity error
DC bus fuse and blown fuse Uncommanded motion
Transient voltage suppression Overspeed
Electronic instantaneous overcurrent Feedback transducer failure
Electronic I2t motor thermal overload Memory malfunction
Electronic braking unit overcurrent Processor running fault
  Heat sink overtemperature

Power Range

Input Voltage

2400 Series (Modular AC)

2420 Series (Integrated AC)

2450 Series (Modular DC)

230 V AC 11/2-75 hp (1.1-56 kW) 11/2-40 hp (1.1-30 kW) 11/2-150 hp (1.1-110 kW)
460 V AC 11/2-1000 hp (1.1-746 kW) 11/2-60 hp (1.1-45 kW) 11/2-800 hp (1.1-597 kW)
575 V AC 11/2-1000 hp (1.1-746 kW)

Consult factory for other powers. Other voltages require appropriate derating.